Numerous support stands for raising and lowering a load are known in the prior art. Some manually raise and lower the load by means of a rack and pinion as disclosed in U.S. Pat. Nos. 3,464,655 and 3,806,395, while others as shown in U.S. Pat. Nos. 4,655,426 and 5,337,678 utilize a manually operated screw jack to raise and lower the load. However, electro-mechanical actuators for raising and lowering loads are disclosed in U.S. Pat. Nos. 3,608,462; 4,557,454; 5,224,429 and 5,495,811, whereas U.S. Pat. No. 4,750,970 discloses an electrically operated rack and pinion for moving a framework back and forth in a horizontal direction.
Since most of the loads disclosed in the prior art were relatively light or were positioned immediately adjacent the raising and lowering column, the problems of a heavy cantilevered load and the locking of such load in a specific position on a cantilever arm were not fully recognized or properly dealt with. That is, as shown in the cited prior art, either multiple telescoping support columns or large heavy plates with long rollers on opposite sides thereof were utilized to compensate for the inherent binding effect produced with a cantilevered load. Further once the cantilevered load were raised on a cantilever arm, no convenient mechanism was available for locking the load in a desired rotational position on such arm.
Accordingly, it is an object of the present invention to provide an improved apparatus for raising and lowering a cantilevered load which prevents the cantilever arm from binding on the support post while reducing friction within the operating mechanism.
A further object has been to provide a unique remote controlled locking mechanism for locking a load in a desired position on a raised cantilever arm.